The issue boils down to statements that, at first glance, appear to directly contradict one another:

According to statements Bain filed with the SEC, Romney was the "chairman, CEO, and president" of Bain from 1999-2002.

According to Romney, Romney left Bain in 1999 and had "no input on investments or management of companies after that point."

Beyond determining whether these statements are accurate--or whether Bain misled the SEC or Romney has been misleading the public--the reason this issue is important is that Romney wants to disavow responsibility for anything Bain or Bain companies did after early 1999.

And one of the things that Bain did after early 1999, as Dan Primack of Fortune points out, is invest in a company called Stericycle whose services included the disposal of aborted fetuses.

For obvious reasons, an investment in a company that performed this service might hurt Romney's standing with the right-to-life voters in the Republican party, even though Romney was pro-choice at the time the investment was made.

And Romney also wants to disavow responsibility for many layoffs that Bain engineered after 1999, an issue he has had to deal with since running for Governor.

When the statements above are examined closely, however, it becomes clear that the Romney campaign may be treading a very fine rhetorical line here--one that it believes might allow Romney to dodge both bullets (the accuracy of his public statements and Bain's decisions).

Specifically...

Note that the Romney campaign does not deny that Romney was "chairman, CEO, and president" of Bain from 1999-2002.

What the Romney campaign says instead is that Romney "left" Bain in 1999 and had "no input on investments or management of companies after that point."

So, read to the legal letter, both of those statements may technically be true (or at least defensible).

Romney did leave Bain in 1999, at least for a leave of absence (he went to run the Olympics).

And it is possible that, once he left, he no longer had direct input into investment or management decisions.

However ...

As "Chairman, CEO, and President" of Bain, he damn well would have remained responsible for these decisions. In which case, saying he had "left" and implying that he had no involvement or responsibility whatsoever is highly misleading.

The CEO of a car company may not have input into the decision of what specific cars the company makes or where it makes them (though he or she obviously could if s/he wanted), but this CEO is unequivocally responsible for these decisions.

Similarly, if Romney was CEO of Bain at the time it made the Stericycle decision, as well as the company layoffs and other unpleasant facts that Candidate Romney would like to disown, he certainly was responsible for these decisions.

So, enough with walking a fine line rhetorically.

Here are the questions that the Romney campaign needs to answer:

Was Mitt Romney "chairman, CEO, and President" of Bain from 1999-2002 (even if he had physically "left" and was spending 100% of his time running the Olympics)? If the answer is "yes," then Romney is responsible for what Bain did during that period--full stop.

OR

Were the filings submitted to the SEC inaccurate?

The answer to those two questions cannot be "both." It's one or the other.

And if the answer is that Mitt Romney was chairman, CEO, and president of Bain for the years in which he has long tried to disavow any responsibility for what the firm did, the American public has every right to feel misled.